The overall goal of this project is to develop an understanding of the genetic as well as environmental influences that are involved in the etiology of human esophageal cancer. In North Central China where rates of this cancer are highest in the world, a sample of families has been identified with extraordinary familial aggregation for the disease. The specific purpose of the first phase of these studies is to obtain existing pedigree and epidemiologic information on a limited number of these families, obtain additional data on the base population from which they were drawn, and initiate steps to prospectively follow these families for the development of cancer. Formal genetic and genetic/epidemiologic evaluations will include familial aggregation studies, studies of the transmission or segregation of the disease, and studies that compare lifestyle and dietary aspects between case and control families. Analyses of these data should provide a unique opportunity to understand the genetic and epidemiologic components of esophageal cancer.